PROJECT SUMMARY/ABSTRACT Approximately 160,000 young infants ?60 days of age are evaluated for fever in a U.S. emergency department (ED) annually. Because of the low but uncertain risk of invasive bacterial infection (i.e., bacteremia and/or bacterial meningitis), well-appearing infants ?60 days of age with fever (i.e., febrile infants) routinely undergo extensive invasive testing and are often hospitalized. Specifically, nearly 100,000 febrile infants undergo lumbar puncture and are hospitalized annually, at a total estimated cost of $400 million, though only 2% will have an invasive bacterial infection. In prior investigations, up to 20% of febrile infants have experienced an iatrogenic complication and 98% of parents have reported considerable stress with this management strategy. While several models have been developed to identify febrile infants at low-risk of a bacterial infection, approximately 1% of ?low-risk? infants have an invasive bacterial infection. Consequently, there is widespread variability in the management of febrile infants that is often due to differences in physician's tolerance for risk. As the benefits of invasive testing and hospitalization do not clearly outweigh the potential harms, decisions on how to manage febrile infants should be informed by parents' values and preferences and made through a shared decision-making (SDM) process. The objective of this project is to develop and test an evidence-based parent-centered care tool (e-CARE) to ensure that parents of febrile infants are optimally informed and able to participate in SDM in the unfamiliar, time-pressured environment of the ED. To accomplish this objective, we will conduct a rigorous qualitative investigation to learn the preferences of parents, attending physicians, and nurses for the content, design, and implementation of e- CARE. We will then develop, test, and refine e-CARE, and will conduct a pilot trial to test the acceptability of e- CARE and the feasibility of performing a clinical trial to assess the impact of e-CARE on outcomes. Paul L. Aronson, MD, is an Assistant Professor of Pediatrics and of Emergency Medicine at the Yale School of Medicine. During his current KL2 award, Dr. Aronson has received training in research methodology, biostatistics, clinical prediction modeling, and cost effectiveness. For this K08 award, the career development plan builds on this foundation through coursework and mentorship in SDM, qualitative research, clinical trials, and implementation science. This award will position Dr. Aronson to achieve his long-term goal to become an independent health services researcher with expertise in the development and implementation of management strategies for febrile infants that incorporate SDM. Leveraging the research infrastructure Dr. Aronson has developed through the Febrile Young Infant Research Collaborative, his intermediate-term research objective is to perform a multicenter clinical trial to evaluate the effect of e-CARE on outcomes in febrile infants, and to evaluate how best to implement e-CARE into clinical practice. Ultimately, e-CARE has the potential to align the use of invasive testing and hospitalization of febrile infants with informed parents' values and preferences.